Andreas Neidel, Erhan Cagliyan, Anne Jahnke, Susanne Riesenbeck, Thomas Ullrich, Sebastian Wallich
March 1, 2013
Several metallic heat shields of the combustion chamber of a large industrial gas turbine were affected by thermo-mechanical cracking after long service exposure. The base metal Alloy 617 is coated with a thermal barrier system. While microstructural evidence allowed the exclusion of creep damage as the metallurgical cause of failure, other microstructural features led to the conclusion that the affected components were massively overheated and experienced service temperatures of up to 1100 °C. There are several possible reasons for such overheating, ranging from burner failure and lack of cooling to abuse in service. A discussion of these factors is not the subject of this case study.